Children and adolescents exposed to the trauma of the 9/11 WTC terrorist attack continue to have an effect on their neuro-psychological and emotional development as they grow into adulthood. In our recently completed NIOSH funded Stress & Well-Being (S&W) Study, we comprehensively assessed, a representative sample (N= 1,000) of youth who were between the ages of <18 years of age on 9/11. Fifteen years later, we found that highly exposed children developed separation anxiety, or panic disorder at four times the rate of a non-exposed control (8% compared to 2% for each disorder). The neurobiology of anxiety disorder suggests deficits in several neuronal networks, including emotional regulation, cognitive control and memory. These circuits mature during childhood and adolescence, and therefore are most vulnerable to trauma during this period. Yet, to date, there are no neuroimaging studies examining these neuronal networks in young adults exposed to 9/11 trauma as children. As these individuals enter adulthood with potential brain development alterations, it is imperative that we understand the neurobiological impact of 9/11 exposure on the relevant brain circuitry, if we are to mitigate the effects in a timely fashion. We propose to investigate the neural underpinnings of emotional processing and cognitive control using event related potentials (ERPs) and multimodal magnetic resonance imaging (MRI) in 105 young adults ages 21 to 32 in the following 3 subgroups: 1) 9/11 highly exposed with anxiety disorder (HEAnx+); 2) 9/11 highly exposed with no anxiety disorder (HEAnx-); and, 3) no 9/11 exposure with no anxiety disorder (LEAnx-). We will compare performance, and brain structure, function and connectivity between groups to capture differences in emotional reactivity, and in the interaction of trauma memory and cognitive control processes. This study will broaden the neurobehavioral understanding of our unique 9/11 cohort of young adults exposed to 9/11 as children or adolescents. The aim of the Multimodal Neuroimaging of Cognitive and Emotional Networks in Young Adults Exposed to 9/11 as Children Study (E&M Study) is to examine the neural circuits of cognitive control, memory and emotion, which are most susceptible to the effects of trauma during brain maturation in childhood and adolescence. This study will assess, for the first time, brain structure and function, using ERP and MRI, of young adults with and without anxiety disorders (ages >17-32), who were highly exposed to 9/11 during childhood (ages 4-<18). We will employ tasks that target attention to salient stimuli, memory and emotion regulation in conjunction with psychological measures of emotional reactivity, and anxiety. Importantly, the study will provide an initial understanding of the emotional, memory and cognitive systems, and inform the trajectory of psychiatric disorders in this maturing cohort. Furthermore, it will could lead to brain-based prevention strategies for children exposed to 9/11, with the potential to facilitate interventions for trauma exposure in general